Shell-and-tube heat-exchanger



Dec. 14, 1965 c. GQEBEL 3,223,154

SHELL-AND-TUBE HEAT-EXCHANGER Filed Jan. 25, 1962 2 Sheets-Sheet 1 ZNVENTOR. l6 37 CLARENCE J. GOEBEL Dec. 14, 1965 c. J. GOEBEL 3,223,154

SHELL-AND-TUBE HEAT-EXCHANGER Filed Jan. 25, 1962 2 sheet-sneet 2 FIG.8

INVENTOR.

CLARENCE J. GOEBEL United States Patent 3,223,154 SHELL-AND-TUBE HEAT-EXCHANGER Clarence J. Goebel, Racine, Wis, assiguor to Young Radiator Company, Racine, Wis., a corporation of Wisconsin Filed Jan. 25, 1962, Ser. No. 168,765 4 Claims. (Cl. 165-158) This invention relates to heat exchangers of the type commonly known as shell-aud-tube.

A shell-and-tube heat exchanger is designated so because of the character of its structure. wherein a core unit is telescopically located, is a length of cylindrical tubing. To the ends of the tubing, i.e., the shell, are bonded flange elements for the attachment of fittings generally designated as bonnets.

These flange elements as a rule have ports formed therein for the connection of conduits leading from and to the source of fluid that is to flow through the labyrinth within the core unit. The bonnets, likewise, contain ports for the connection of conduits from and to the source of fluid that is to flow through the core unit. The bonnets, as a rule, are bolted to the flange elements.

The core unit comprises a battery of closely-spaced, parellel tubes spanning and supporting headers. Such a core unit, designated as the tube part of the shell-andtube heat exchanger, is dimensioned to snugly fit in the shell with the headers sealing off the labyrinth around the core unit.

It is practically universal with the manufacturers of the smaller-size heat exchangers of this type, to make these end fittings, and the bonnets, castings or forgings.

The main objects of this invention are to provide an improved structuring of shell-and-tube type of heat exchangers; to provide an improved structuring of shelland-tube type heat exchangers wherein the bonnets and the headers are formed of sheet metal; to provide an improved relative formation of the ends of the shell, the core unit headers and the bonnets to permit facile telescopic inter-seating of their respective perimeters and a one-operation unitary bonding thereof together; to provide improved bonnets of this kind for singleor multiplepass shell-and-tube type heat exchangers; to provide improved bonnets of this kind which permit mounting thereon any of the various forms of standard type fittings for the attachment of conduits from and to the fluid sources; and to provide an improved shell-and-tube type of heat exchanger of such simple structure as to make its manufacture extremely economical, its assembly and bonding most facile, and the scope of its utility comparable to, if not exceeding any of the conventional forms of this type of heat exchanger heretofore marketed.

In the adaptation shown in the accompanying drawlngs;

FIG. 1 is a side elevation, partly sectional, of one adaptation of a shell-and-tube type of heat exchanger constructed in accordance with this invention;

FIG. 2 is a reduced, fragmentary, partly sectional and partly elevational view of a modified form of bonnet and conduit fitting;

FIG. 3 is an elevational view of the right-hand end of the heat exchanger shown in FIG. 1 as taken on the plane of the line 33 of that figure;

FIG. 4 is a transverse sectional view of the heat exchanger shown in FIG. 1 taken on the plane of the line 44 of that figure;

FIG. 5 is an enlarged, fragmentary, sectional view of the portion of the heat exchanger of FIG. 1 included in the circle A of that figure;

FIG. 6 is a fragmentary view of another modified form of bonnet and conduit fitting;

The housing,

" 3,223,154 Ce Patented Dec. 14, 1965 FIG. 7 is an inside end perspective of the left-hand bonnet of FIG. 1;

FIG. 8 is a similar view of the opposite bonnet of FIG.

FIG. 9 is a reduced-size, sectional detail of the righthand bonnet as viewed from the plane of the line 99 of FIG. 3;

FIG. 10 is a right-hand end view of a heat exchanger constructed in accordance with this invention, with one type of support mounting therefor and wherein the conduit fitting is of the type shown in FIG. 7; and

FIG. 11 is a fragmentary, side view of another type of support mounting for heat exchangers constructed in accordance with this invention.

The essential concept of this invention, for structuring a shell-and-tube type heat exchanger, involves the forming of the core-unit headers, end bonnets, as well as the shell itself, of sheet metal with their respective open perimentrical portions so relatively dimensioned and contoured as to permit interfitting telescopic seating for a one-operation interbonding of the perimetrical portions of the headers, bonnets and shell and then subsequently bonding to the shell and to the end bonnets, respectively, any of several forms of standard fittings for the connection of conduits to direct the fluid flow to, through and from the core unit and the surrounding labyrinth within the shell.

A shell-and-tube heat type exchanger embodying the foregoing concept comprises a shell 12, a core unit 13, end bonnets 14 and various forms of conduit fittings 16.

The shell 12 is a conventional unit, being a section of tubing of suitable material of required diameter and length to permit the assembly therein and on of the other units to function eifectively in securing the desired cooling of fluids for a particular type of equipment. As most clearly shown in FIGS. 1 and 5 short perimetrical portions 17 of the ends of the shell 12 are flared an amount practically equal to the thickness of the metal from which the shell 12 is formed.

The core unit 13 is a conventional battery of closelyspaced tubes 18 spanning and supporting a pair of headers 19. In this development the headers 19 are formed of stampedor possibly spunsheet metal of a gage approximating that of the shell 12. The perimetrical flanges 21 thus formed on each of the headers 19 is of an outside diameter to insure telescopic fitting into the flared ends 17 of the shell 12. In axial length these flanges 21 preferably are slightly less than the depth of the flared ends 17 of the shell 12 (see FIG. 5).

The end bonnets 14 are stamped or die-formed units. Whatever their particular contour, they are dish-shaped and of an axial depth suflicient to provide a rather considerable amount of space between the opposed faces of the headers 19 and the respective bonnets 14. The contour of these end bonnets 14 is determined, in a large measure, by the character of the fittings 16 which are to be bonded thereto and which, in turn, may be determined by the use to which such a structured heat exchanger is to be subjected, as presently will be described more fully. Whatever the contour of these bonnets 14 the perimeter of the larger open end is dimensioned to have a snug telescopic fit into the respective header flanges 21, as is most clearly shown in FIGS. 1 and 5.

In the forming of the header 19 and the end bonnets 14 of sheet metal, of approximately the same gage as that of the shell 12 and the relative dimensioning of the shell flared ends 17, the header flanges 21 and the larger open ends of the end bonnets 14 for telescopic seating as that herein shown, makes possible a one-operation bonding of these three parts together at each end of the shell 12. The result is a structure fully as durable as any of the shell-and-tube heat exchangers heretofore marketed with cast or forged shell flanged elements, core-unit headers and end bonnets. Moreover, the structuring of these three parts of sheet metal and their interbonding can be effected at a very great saving in time and material over that involved on the heretofore conventional structuring of and inter-bonding of these parts.

Obviously, the headers 19, with the telescoped ends of the bonnets 14, could be bonded in unflared ends of the shell 12. However, the flaring of the shell ends permits disposing the outer circle of tubes 18 so close to the inside wall of the shell as to reduce to a minimum the bypassing of the fluid flow through the circumferential portion of the labyrinth of the core unit 13.

The dish-shaped end bonnets 14 have their contours accommodated to at least the two factors of the manner of using the heat exchanger and the form of the fittings 16 desired for connecting conduits for directing the fluidflow through the core unit 13 and through the labyrinth within the shell 12 and around the core unit 13 from and to the fluid sources.

For a double-pass heat exchanger of this construction, such as illustrated in FIG. 1, the fitting 16 has to be a dual port unit for one end bonnet 14. This may be a pipe threaded unitary casting 22 (FIGS. 1, 3, 8 and 9) or two pipe nipples 23 (FIGS. 2 and By reason of such specific fittings. 22 and 23 the end bonnet 14, wherein either is mounted, has to have the end wall flat to provide ample space for the fittings 22 and 23 and to permit the insertion of a baffie 26 diametrically across the interior of the end bonnet (FIGS. 1-3, 8 and 10). This baffle 26, as here shown, is a sheet metal stamping in length equal to the interior diameter of that particular end bonnet 14 and of a width equal to the axial depth of such an end bonnet. The baffle 26 is strengthened by a longitudinal rib 27 and has a pair of integral lugs 28 for reinforcing the bonding of the baffle 26 to the inner face of the end wall 29 of the bonnet. When such end bonnet 14 is bonded in place to the opposed header 19 the free edge of the bafl le 26 firmly contacts the header 19 between the two adjacent rows of tubes 18 and may be bonded to the header 19.

The unitary-threaded type fitting 22 has its base part 30 of elongated form with semicircular ends as shown by the line 31 in FIG. 3. An inner portion of the base part 30 is recessed, on a slight taper (FIG. 9), to form a base extension 32 to fit in an opening 33 in the end wall 29 of the above-designated end bonnet 14. The sides and ends of the base extension 32 and the wall opening 33 are parallel and concentric, respectively, with the sides and ends of the base part 30 as defined by the line 31 in FIG. 3. Such a recessed base extension 32 provides ample contacting areas between the end bonnet 14 and the fitting 22 to insure an effective bonding of these parts (see FIG. 9).

The pipe-nipple type of fitting 23 (FIG. 2) is telescoped and bonded in circular openings 34 in the end wall 29 of an end bonnet. As here shown these openings 34 are formed by turning in the perimetrical portions 36 to afford substantial contact with the ends of the nipples 23 and insure an effective bonding together thereof.

The other end bonnet 14, for such a double-pass heat exchanger, has the side wall tapered to a smaller-diameter opening 35 and the fitting 16 is in the nature of a closure cap 24 (FIGS. 1 and 7).

For a single-pass heat exchanger of this structure the fitting 16 desired for each end bonnet 14 may be a standard pipe-threaded collar 37 bonded in a single opening 38 in the smaller end of each of the end bonnets 14 (FIG. 6).

With these collars 37, as with the pipe connectors 23, the perimetrical portions 39 of the open ends of the two end bonnets 14 are turned in to afford substantial contact of the parts for the most effective bonding.

The fittings 16 for the shell 12 generally are threaded collars 40 with one end concave concentric with the outer circumference of the shell 12. These collars 40, as here 4 shown, are bonded over ports 41 inwardly adjacent opposite ends of the shell 12, (FIG. 1).

Many are the ways in which mountings may be arranged for heat exchangers constructed in accordance with this invention. Two different mountings. are shown in FIGS. 10 and 11.

Where it is most practical to mount such a heat exchanger on some kind of frame, the mounting requires only straps 42 embracing the shell 12 inwardly of the end bonnets 14 with the ends of the straps 42 secured by boltand-nut fasteners 43 to a frame part 44. Where, however, it is most practical to suspend such a heat exchanger from an overhead frame 44, a flanged elbow 45 may be bonded to the one end bonnet 14 and secured to the frame part 44 by bolt-and-nut fasteners 43 (FIG. 11). In this latter case the frame part 44 may be the lower tank and heat exchanger radiator from which the fluid flows through the core unit 13.

The manner of assembling the above-described heat exchangers follow very much the conventional procedure with heat exchangers of this type, where the core-unit headers are larger in diameter than the inner diameter of the shell 12.

One of the headers 19 is positioned either on a flat surface or in a vertical position in a suitable jig. Three or four pilot tubes 18 have their ends inserted through holes in the one header 19, intermediate the center and the periphery of the header. The protruding ends of these pilot tubes are flared slightly to insure their firm positioning in the one header 19.

The shell 12 then is shifted in over these few tubes and has the one'header seated in the one flared end 17. Baflle spacers (not here shown) and the baffles 31 are successively slipped down on these pilot tubes 18. The other header 19 then is set over the other ends of these pilot tubes 18 and the other ends of such tubes are flared slightly to insure firm juncture with the other header 19. Thereupon, the remaining tubes 18, one at a time, are inserted through the registering holes in the other header 19, in the baifies 31 and in the one header 1'9. Successively, these remaining tubes 18 have their ends flared sufficiently to form firm junctures with both headers 19. The tube ends then are bonded to the headers 19 in any conventional manner.

Next the end bonnets 14 are successively set with the perimeters of their larger open ends telescoped into the header flanges 21 and the shell-flared ends 17, whereupon these parts are brazed together in one operation. Preferably, this would be effected by placing a brazing ring (not shown) in the gap 47 (FIG. 5) and subjected to the required heat as generally is practiced for this mode of bonding.

At this stage of the assembly, the fittings 16 are not yet secured to the respective end bonnets 14. Hence, comparatively large openings 33, 34 and 35 permit examination and, if necessary repair, of the tested bonds of the tubes 18 in the headers 19 and of the shell 12, headers 19 and end bonnets 14.

Upon ascertaining that all the tested bonds are satisfactory, the respective fittings 22, 23, 24 and/or 37 are brazed in place in the respective openings 33, 34 and 35 of the bonnets 14, in a conventional manner.

Other variations. and modifications of the details and structure and arrangement, other than those herein shown, may be resorted to within the spirit and coverage of the appended claims.

I claim:

1. A shell-and-tube heat exchanger comprising,

(a) a cylindrical single piece shell formed of sheet metal with open ends, (b) a core unit formed of a bundle of tubes spanning and supporting a pair of circular headers each of sheet metal and having an integral perimetrical flange telescop- 2. A heat exchanger of the type set forth in claim 1 wherein the ends of the shell are flared to a diameter greater than the intermediate portion of the shell and the header flanges are telescopically seated in and bonded to the flared ends of the shell.

3. A shell-and-tube heat exchanger comprising a cylindrical single piece shell formed of sheet metal with open ends, a core unit formed of a bundle of tubes spanning and supporting a pair of circular headers each of sheet metal and having an integral perimetrical flange telescopically seated in and bonded to one end of the shell, 21 pair of circular bonnets each dish-shaped formed of stamped sheet metal having its open perimeter telescopically seated in and bonded to a header flange, and a fitting standard threaded having a pair of spaced openings bonded in the end of one bonnet for connection of conduits leading from and to a fluid source, a baflle separately formed and dimensioned for diametrical bonded disposition across the interior of the one bonnet between the fitting openings spanning the space between the bonnet and the opposed header to effect a two-way fluid flow through the core unit, and a pair of fittings standard threaded bonded to the shell inwardly of the core-unit headers for connection to conduits leading from and to a fluid source to effect a fluid flow through the labyrinth around the core unit.

4. A shell-and-tube heat exchanger comprising,

a cylindrical single piece shell formed of sheet metal with open ends,

a core unit formed of a bundle of tubes spanning and supporting a pair of circular headers each of sheet metal and having an integral perimetrical flange telescopically seated in and bonded to one end of the shell,

a pair of circular bonnets each dish-shaped formed of stamped sheet metal having its open perimeter telescopically seated in and bonded to a header flange, and

a pair of fittings each standard threaded bonded to the end of one of the bonnets in axial relationship to the shell for connection to conduits leading from and to a fluid source to effect a One-way flow of fluid through the core unit, and

a pair of fittings standard threaded bonded to the shell inwardly of the core-unit headers for connection to conduits leading from and to a fluid source to effect a fluid flow through the labyrinth around the core unit.

References Cited by the Examiner UNITED STATES PATENTS 1,787,086 12/1930 Pew 165-161 1,958,226 5/1934 Askin 165-150 2,864,489 12/1958 Booth et al 165160 2,878,656 3/1959 Domal 165150 FOREIGN PATENTS 866,021 4/ 1961 Great Britain.

FREDERICK L. MATTESON, JR., Primary Examiner.

CHARLES SUKALO, Examiner. 

1. A SHELL-AND-TUBE HEAT EXCHANGER COMPRISING, (A) A CYLINDRICAL SINGLE PIECE SHELL FORMED OF SHEET METAL WITH OPEN ENDS, (B) A CORE UNIT FORMED OF A BUNDLE OF TUBES SPANNING AND SUPPORTING A PAIR OF CIRCULAR HEADERS EACH OF SHEET METAL AND HAVING AN INTEGRAL PERIMETRICAL FLANGE TELESCOPICALLY SEATED IN AND BONDED TO ONE END OF THE SHELL, (C) A PAIR OF CIRCULAR BONNETS EACH DISH-SHAPED FORMED OF STAMPED SHEET METAL HAVING ITS OPEN PERMIETER TELESCOPICALLY SEATED IN AND BONDED TO A HEADER FLANGE, AND (D) FITTINGS STANDARD THREADED BONDED IN THE ENDS OF THE RESPECTIVE BONNETS, AND TO THE SHELL INWARDLY OF THE CORE-UNIT HEADERS FOR CONNECTION OF THE CONDUITS LEADING FROM AND TO FLUID SOURCES TO EFFECT A FLUID FLOW, RESPECTIVELY, THROUGH THE CORE UNIT AND THE LABYRINTH AROUND THE CORE UNIT. 